Autoscale worker nodes on a cluster to increase or decrease the number of resources available. Autoscaling for worker nodes is configured in the machine pool definition if you are configuring an existing cluster.

Additionally, you can configure autoscaling on the default machine pool when you create the cluster using interactive mode.

About autoscaling nodes in a cluster

The cluster autoscaler increases the size of the cluster when there are pods that failed to schedule on any of the current nodes due to insufficient resources or when another node is necessary to meet deployment needs. The cluster autoscaler does not increase the cluster resources beyond the limits that you specify.

The cluster autoscaler decreases the size of the cluster when some nodes are consistently not needed for a significant period, such as when it has low resource use and all of its important pods can fit on other nodes.

Enabling autoscaling nodes in an existing cluster

Configure autoscaling to dynamically scale the number of worker nodes up or down based on load.

Successful autoscaling is dependent on having the correct AWS resource quotas in your AWS account. Verify resource quotas and request quota increases from the AWS console.

Procedure
  1. To identify the machine pool IDs in a cluster, enter the following command:

    $ rosa list machinepools --cluster=<cluster_name>
    Example output
    ID        AUTOSCALING   REPLICAS    INSTANCE TYPE  LABELS    TINTS   AVAILABILITY ZONES
    default   No            2           m5.xlarge                        us-east-1a
    mp1       No            2           m5.xlarge                        us-east-1a

    Decide which machine pool ID you want to configure.

  2. To enable autoscaling on a machine pool, enter the following command:

    $ rosa edit machinepool --cluster=<cluster_name> <machinepool_ID> --enable-autoscaling --min-replicas=<number> --max-replicas=<number>
    Example

    Enable autoscaling on a machine pool with the ID mp1 on a cluster named mycluster, with the number of replicas set to scale between 2 and 5 worker nodes:

    $ rosa edit machinepool --cluster=mycluster mp1 --enable-autoscaling --min-replicas=2 --max-replicas=5
Additional resources

Managing objects with the rosa CLI